Process and apparatus for shirring tubular casings

Abstract

This invention relates to an improvement in the process for shirring cylindrical tubular casings, especially artificial sausage casings of synthetic material, in which an inflated casing is conveyed in the direction of its longitudinal axis and shirred, with pleating, against a counter-force by shirring forces acting upon the circumference of the casing, the improvement comprising that the forces acting upon the surface of the casing do so continuously and simultaneously, at equal intervals, at a plurality of points on at least two straight lines extending parallel to and symmetrically about the longitudinal axis of the casing, the action being at right angles to the longitudinal axis of the sausage casing, and circumferentially thereof, and, simultaneously, in the direction of the longitudinal axis of the casing, against said counter-force. The invention also relates to an apparatus for performing the process.

What is claimed is: 
     
       1. In the process for shirring cylindrical tubular casings, especially artificial sausage casings of synthetic material, in which an inflated casing is conveyed in the direction of its longitudinal axis and shirred, with pleating, against a counter-force by shirring forces acting upon the circumference of the casing, the improvement which comprises applying the shirring forces by at least two worm means, the longitudinal axes of which extend parallel to the longitudinal axis of the inflated casing and the teeth of which are in frictional contact with the inflated tube and depress it, said worm means rotating about their longitudinal axes and simultaneously revolving at a radial distance around the circumference of the inflated tubular casing.   
     
     
       2. A process according to claim 1 in which the shirring forces are applied by four worm means. 
     
     
       3. A process according to claim 1 in which the casing is successively contacted by the teeth of the worm means along a helical line corresponding to the pitch of the worm means.